Prosauropods and the origin of plateosaurus
The plateosaurus was one among the first set of dinosaurs who were named formally though it must be mentioned here that at that point not much research had been carried out to judge its eligibility in qualifying as a dinosaur since in those early times not much evidence had been available regarding these vertebrate animals which strode on the surface of the earth some 230 million years ago.
The plateosaurus is considered to be a descendent of the plateosaurid prosauropod dinosaur and it is popularly referred to as the ‘flat lizard’. In order to understand the characteristic features of the plateosaurus, it is necessary for one to gain an idea regarding the prosauropods. The prosauropods basically refer to a particular group of herbivorous dinosaurs who existed during the Triassic and the Jurassic era.
These prosauropods were initially considered to be the ancestors of the gigantic sauropods though later it was revealed that they actually constituted a different group along with the sauropods. The plateosaurus is considered to be the foremost among the various prosauropods and was also the first of the prosauropod family to be discovered.
The plateosaurus is believed to have existed about 200 million years ago in parts of the European continent during the late Triassic period.
The very first specimen of the plateosaurus was discovered in 1834 in Germany by Johann Friedrich Engelhardt and it was after an extensive study of the leg bones and vertebrae thus collected that these new kind came to be known as the plateosaurus. The name plateosaurus has been derived from the Greek ‘platys’ referring to something flat while ‘saurus’ refers to lizard.
After the first excavations in Germany, during the initial years of the 20th century there were several more plateosaurus remains which were unearthed in several other regions of Europe along with other dinosaur variants. More recently in 1997 several fossilized remains of the plateosaurus were unearthed from the North Sea while a decade later in 2007 some more remains have been recovered from Switzerland.
The plateosauridae is a subfamily of the prosauropods and it was named after the most prominent prosauropod i.e. the plateosaurus. Initially after its discovery, the plateosaurus was considered to be a variant of the theropod family and it was much later that Huene classified it as a category under the prosauropods. It must also be pointed out at this juncture that the plateosaurus fossils are the most common forms of dinosaur fossils excavated on different parts of the earth.
There are several variants that are often referred to as a form of the plateosaurus but it is difficult to make out their essential features and characteristics. Therefore after massive research there are two main classifications of the plateosaurus. These are the P. engelhardti and the P. longiceps. The various remains and specimens of both these kinds of plateosaurus have been recovered from sections of Germany and there are innumerable evidences available for further research. The P. longiceps is the most prevalent among the two and it has a lighter body configuration and longer limbs and a protruding snout compared to the P. engelhardti.
This prosauropod would be about 10 meters maximum in length while its average weight was around 700 kgs. Compared to the various other prosauropods the structure of the skull of this dinosaur was more sturdy and even though the head was quite insignificant in weight and size than the remaining parts of the body.
The plateosaurus had the dominant physical features of most prosauropods and it was an herbivore, essentially lightweight with a long and steady neck with a small skull located on the pinnacle. The plateosaurus had four sets of openings on the skull known as fenestrae and these openings were located both on the space between the eyes and the nose and also towards the back portion of the skull.
The eyes were located towards the side rather than in a central position which refers to the fact that they could keep a close watch on attackers. The long neck of the plateosaurus comprised of nine cervical vertebrae and the snout which protruded outwards was long and elongated and they contained the teeth located on the upper and lower jaw and it is these teeth which provided substantial evidence to suggest that these plateosaurus were plant eaters.
Similar to most plant eaters or herbivorous dinosaurs, the plateosaurus possessed leaf-shaped small teeth in the upper and lower jaw and these teeth on the maxilla, premaxilla and the dentary, together comprised its entire dental arrangement. It is to be noted that these small jagged teeth greatly benefited the plateosaurus by helping it to consume and digest the plant matters. Moreover, an extensive study of the plateosaurus skull has also proved that they possessed cheeks where they could store the plant components before eating them.
The plateosaurus mostly fed on cycads and conifers and therefore it is evident that the long neck of the plateosaurus was immensely helpful in helping it to collect food. However, the absence of cheek teeth forced the plateosaurus to consume gastroliths and a similar tendency ahs also been observed in other prosauropods as well. Towards the posterior section of its body, the plateosaurus had a long tail which was made of about forty caudal vertebrae and it played a significant role in aiding to balance the entire body weight.
In the plateosaurus the forelimbs were shorter than the hind limbs and these limbs were made up various digits or finger. It is interesting to note that in most cases, the plateosaurus has been referred to as a four limbed dinosaur though various evidences have proved that prosauropods like the plateosaurus are unable to use their forelimbs for the purpose of roaming around or even standing.
Therefore it is usually believed that the plateosaurus uses its forelimbs in order to collect food from higher elevations like from the branches of trees while its hind limbs are used entirely for the purpose of traveling from one place to another.
It is interesting to note that the various fossils and specimens of the plateosaurus have suggested that there were certain discrepancies in the sizes of different plateosaurus and this is usually attributed to the level of growth in a single plateosaurus which in its turn was governed by various environmental factors.
However it is popularly believed by scientists and paleontologists alike that the plateosaurus had a faster rate of growth than most of the different varieties of dinosaurs. Some evidences prove that these dinosaurs usually traveled in groups during the Triassic period while certain other fossil remains have suggested that they inhabited in seclusion in dry elevated areas.